import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Welcome to Flutter',
      home: new Scaffold(
//        appBar: new AppBar(
//          title: new Text('Welcome to Flutter'),
//        ),
        body: new Center(
//          child: new Text('Hello World'),
          child: new RandomWords(),
        ),
      ),
    );
  }
}

class RandomWords extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return RandomWordsState();
  }
}

class RandomWordsState extends State<RandomWords> {
  final _suggestions = <WordPair>[];
  final _biggerFont = const TextStyle(fontSize: 18);

  // 记录喜欢的数据
  final Set<WordPair> _saved = new Set<WordPair>();

  // 创建滚动试图
  Widget _buildSuggestions() {
    return new ListView.builder(
      padding: const EdgeInsets.all(16),
      itemBuilder: (BuildContext _context, int i) {
        if (i.isOdd) {
          return new Divider(
            color: Colors.blue,
          );
        }

        final int index = i ~/ 2;
        if (index >= _suggestions.length) {
          _suggestions.addAll(generateWordPairs().take(10));
        }
        return _buildRow(_suggestions[index]);
      },
    );
  }


  Widget _buildRow(WordPair pair) {
    final bool alreadySaved = _saved.contains(pair);

    return new ListTile(
      title: new Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: new Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }

  void _pushSaved() {
    Navigator.of(context).push(new MaterialPageRoute(builder: (context) {
      final tiles = _saved.map((pair) {
        return new ListTile(
          title: new Text(
            pair.asPascalCase,
            style: _biggerFont,
          ),
        );
      });
      final divided =
          ListTile.divideTiles(tiles: tiles, context: context).toList();
      return new Scaffold(
        appBar: new AppBar(
          title: new Text('Saved Suggestions'),
        ),
        body: ListView(children: divided),
      );
    }));
  }


  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Startup Name Generator'),
        actions: <Widget>[
          new IconButton(icon: const Icon(Icons.list), onPressed: _pushSaved),
        ],
      ),
      body: _buildSuggestions(),
    );
  }
}